Abstract The paper presents the concept of using C 60 fullerenes as streaming electrification process inhibitor in mineral insulating oil. For the research, 20 samples of oil were prepared; one pure and 19 containing from 1 mg/l to 512 mg/l of C 60 . The electrification current was measured using a wireless electrometer spinning disk system for rotational speeds from 0 rpm to 400 rpm. The research revealed the C 60 ability to significantly reduce the constant component of streaming electrification current in mineral transformer oil. The C 60 additive causes also the significant change in flow electrification mechanism as indicated by current versus flow velocity relations.